Fabric diaphragms for seat and backrest of a cushioned chair used in, for example, airplanes are typically stretched between or around two tubes so as to create a flexible surface on which a cushion may be placed and the passenger is seated. The diaphragm is stretched flat across (or front to back). In cases where the tubes are straight, the fabric also will be stretched straight. In cases where the frame is contoured, the diaphragm will follow the contours of the frame, but will still be stretched straight across. Stretching the diaphragm to form a generally flat, non-contoured surface does not provide an optimally comfortable surface upon which to sit for a prolonged duration.
It is therefore an object of the present invention to provide a shaped fabric diaphragm for the seat and backrest of a chair which overcomes the drawbacks of prior fabric diaphragms.